/**
 * Created by Think pad on 2016/4/24.
 */
import java.util.Scanner;

public class sizeyunsuan1 {
    public static void main(String[] args) {
        //输入第一个数
        System.out.println("请输入第一个数");
        Scanner a = new Scanner(System.in);
        double i = a.nextDouble();

        //输入运算符
        System.out.println("请输入运算符");
        Scanner c = new Scanner(System.in);
        String op = c.next();

        //输入第二个数
        System.out.println("请输入第二个数");
        Scanner b = new Scanner(System.in);
        double j = b.nextDouble();

        char z = op.charAt(0);
        System.out.printf("运算结果是：");

        //运算判断
        if(z =='+'){
            System.out.printf("%f",i+j);
        }
        else if(z == '-'){
            System.out.printf("%f",i-j);
        }
        else if(z =='*'|| z == 'x'){
            System.out.printf("%f",i*j);
        }
        else if(z == '/'){
            if(j == 0) System.out.println("除数不能为0");
            else System.out.printf("%f",i/j);
        }

    }
}